Micro-led structure and micro-led chip including same

ABSTRACT

A micro-LED chip includes multiple micro-LEDs. At least one micro-LED of the multiple micro-LEDs includes: a first type conductive layer; a second type conductive layer stacked on the first type conductive layer; and a light emitting layer formed between the first type conductive layer and the second type conductive layer. The light emitting layer extends along a horizontal level from a top edge of the first type conductive layer and a bottom edge of the second type conductive layer. The micro-LED chip further includes a metal layer formed on a portion of the light emitting layer that extends from the top edge of the first type conductive layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalApplication No. 63/131,128, filed on Dec. 28, 2020, the entire contentsof which are incorporated herein by reference.

FIELD

The present disclosure relates to a micro-LED structure and a micro-LEDchip including the micro-LED structure.

BACKGROUND

A micro-light emitting diode (micro-LED) is a device that emits lightusing an electric signal and has a size on the order of micrometers oreven smaller. The micro-LED can be driven at a low voltage such that itis widely implemented in small-sized optical elements. In recent years,the micro-LED has been developed as an illuminating light source byincreasing its efficiency.

SUMMARY

According to one aspect of embodiments of the present disclosure, amicro-LED structure includes: a first type conductive layer; a secondtype conductive layer stacked on the first type conductive layer; and alight emitting layer formed between the first type conductive layer andthe second type conductive layer. The light emitting layer extends alonga horizontal level away from a top edge of the first type conductivelayer and a bottom edge of the second type conductive layer, such thatan edge of the light emitting layer does not contact the top edge of thefirst type conductive layer and the bottom edge of the second typeconductive layer. The bottom edge of the second type conductive layer isaligned with the top edge of the first type conductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED structure includes: a first type conductive layer; a secondtype conductive layer stacked on the first type conductive layer; and alight emitting layer formed between the first type conductive layer andthe second type conductive layer. The light emitting layer extrudesalong a horizontal level away from a top edge of the first typeconductive layer and a bottom edge of the second type conductive layer,such that an edge of the light emitting layer does not contact the topedge of the first type conductive layer and the bottom edge of thesecond type conductive layer. A profile of the second type conductivelayer perpendicularly projected on a top surface of the first typeconductive layer is surrounded by the top edge of the first typeconductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED structure includes a first type conductive layer; a secondtype conductive layer stacked on the first type conductive layer; and alight emitting layer formed between the first type conductive layer andthe second type conductive layer. The light emitting layer extends alonga horizontal level away from a top edge of the first type conductivelayer and a bottom edge of the second type conductive layer, such thatan edge of the light emitting layer does not contact the top edge of thefirst type conductive layer and the bottom edge of the second typeconductive layer. A profile of the first type conductive layerperpendicularly projected on a bottom surface of the second typeconductive layer is surrounded by the bottom edge of the second typeconductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED structure includes a first type conductive layer; a secondtype conductive layer stacked on the first type conductive layer; and alight emitting layer formed between the first type conductive layer andthe second type conductive layer. The light emitting layer extends alonga horizontal level from an edge of the first type conductive layer. Anedge of the light emitting layer is aligned with an edge of the secondtype conductive layer. The edge of the second type conductive layerextends along the horizontal level away from the edge of the first typeconductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED structure includes: a first type conductive layer; a secondtype conductive layer stacked on the first type conductive layer; and alight emitting layer formed between the first type conductive layer andthe second type conductive layer. The light emitting layer extends alonga horizontal level from an edge of the second type conductive layer. Anedge of the light emitting layer is aligned with an edge of the firsttype conductive layer. The edge of the first type conductive layerextends along the horizontal level away from the edge of the second typeconductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. An isolation structure is formedbetween adjacent micro-LEDs, at least a portion of the isolationstructure being formed in the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole chip, the multiple micro-LEDs sharingthe light emitting layer. An isolation structure is formed betweenadjacent micro-LEDs, at least a portion of the isolation structure beingformed in the light emitting layer. A top surface of the isolationstructure is aligned with a top of the light emitting layer, and abottom surface of the isolation structure is under the light emittinglayer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes a first type conductive layer; a secondtype conductive layer stacked on the first type conductive layer; and alight emitting layer formed between the first type conductive layer andthe second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is aligned with a top of the light emitting layer, and abottom surface of the isolation structure is above a bottom surface ofthe bottom spacer and is under the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. at least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole chip, the multiple micro-LEDs sharingthe light emitting layer. The micro-LED chip further includes: a topspacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is aligned with a top of the light emitting layer, and abottom surface under the bottom spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further comprises:a top spacer formed on a top surface of the light emitting layer; abottom spacer formed on a bottom surface of the light emitting layer,wherein an edge of the top spacer is aligned with an edge of the lightemitting layer, and an edge of the bottom spacer is aligned with theedge of the light emitting layer; and an isolation structure formedbetween adjacent micro-LEDs, wherein at least a portion of the isolationstructure is formed in the light emitting layer, a top surface of theisolation structure is aligned with a top of the light emitting layer,and a bottom surface of the isolation structure is aligned with a bottomsurface of the bottom spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes anisolation structure formed between adjacent micro-LEDs, at least aportion of the isolation structure being formed in the light emittinglayer. A top surface of the isolation structure is above the lightemitting layer. A bottom surface of the isolation structure is alignedwith a bottom of the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a bottom surface of the isolationstructure is aligned with a bottom surface of the light emitting layer,and a top surface of the isolation structure is above the light emittinglayer and under the top surface of the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a bottom surface of the isolationstructure is aligned with a bottom surface of the light emitting layer,and a top surface of the isolation structure is aligned with a topsurface of the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a bottom surface of the isolationstructure is aligned with a bottom surface of the light emitting layer,and a top surface of the isolation structure is above the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. An isolation structure is formedbetween adjacent micro-LEDs, at least a portion of the isolationstructure being formed in the light emitting layer. A top surface of theisolation structure is above the light emitting layer, and a bottomsurface of the isolation structure is under the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is above the light emitting layer and under a top surface ofthe top spacer, and a bottom surface of the isolation structure is undera bottom of the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is above the light emitting layer and under a top surface ofthe top spacer, and a bottom surface of the isolation structure is undera bottom of the light emitting layer, and above a bottom surface of thebottom spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is above the light emitting layer and under a top surface ofthe top spacer, and a bottom surface of the isolation structure alignedwith a bottom surface of the bottom spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is above the light emitting layer and under a top surface ofthe top spacer, and a bottom surface of the isolation structure is underthe bottom spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a bottom surface of the isolationstructure is under the light emitting layer, and above a bottom surfaceof the bottom spacer, and a top surface of the isolation structure isaligned with a top surface of the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, and the multiplemicro-LEDs sharing the light emitting layer. The micro-LED chip furtherincludes: a top spacer formed on a top surface of the light emittinglayer; a bottom spacer formed on a bottom surface of the light emittinglayer, wherein an edge of the top spacer is aligned with an edge of thelight emitting layer, and an edge of the bottom spacer is aligned withthe edge of the light emitting layer; and an isolation structure formedbetween adjacent micro-LEDs, wherein at least a portion of the isolationstructure is formed in the light emitting layer, a bottom surface of theisolation structure is under the light emitting layer, and above abottom surface of the bottom spacer, and a top surface of the isolationstructure is above the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, and the multiplemicro-LEDs sharing the light emitting layer. An isolation structure isformed between adjacent micro-LEDs, at least a portion of the isolationstructure being formed in the light emitting layer. A bottom surface ofthe isolation structure is aligned with a bottom of the light emittinglayer, and a top surface of the isolation structure is aligned with atop surface of the light emitting layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, and the multiplemicro-LEDs sharing the light emitting layer. The micro-LED chip furtherincludes: a top spacer formed on a top surface of the light emittinglayer; a bottom spacer formed on a bottom surface of the light emittinglayer, wherein an edge of the top spacer is aligned with an edge of thelight emitting layer, and an edge of the bottom spacer is aligned withthe edge of the light emitting layer; and an isolation structure formedbetween adjacent micro-LEDs, wherein at least a portion of the isolationstructure is formed in the light emitting layer, a bottom surface of theisolation structure is aligned with a bottom surface of the bottomspacer, and a top surface of the isolation structure is aligned with atop surface of the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a top surface of the isolationstructure is aligned with a top surface of the top spacer, and a bottomsurface of the isolation structure is under the bottom spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a bottom surface of the isolationstructure is aligned with a bottom surface of the bottom spacer, and atop surface of the isolation structure is above the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. The micro-LED chip further includes: atop spacer formed on a top surface of the light emitting layer; a bottomspacer formed on a bottom surface of the light emitting layer, whereinan edge of the top spacer is aligned with an edge of the light emittinglayer, and an edge of the bottom spacer is aligned with the edge of thelight emitting layer; and an isolation structure formed between adjacentmicro-LEDs, wherein at least a portion of the isolation structure isformed in the light emitting layer, a bottom surface of the isolationstructure is under the bottom spacer, and a top surface of the isolationstructure is above the top spacer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. A bottom edge of the second typeconductive layer is aligned with a top edge of the first type conductivelayer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. A profile of the second typeconductive layer perpendicularly projected on a top surface of the firsttype conductive layer is surrounded by an edge of the first typeconductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layer iscontinuously formed on the whole micro-LED chip, the multiple micro-LEDssharing the light emitting layer. A profile of the first type conductivelayer perpendicularly projected on a bottom surface of the second typeconductive layer is surrounded by an edge of the second type conductivelayer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer, at least one part of thelight emitting layer being formed between adjacent micro-LEDs. themicro-LED chip further comprises a metal layer formed on the lightemitting layer between the adjacent micro-LEDs.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LEDincludes: a first type conductive layer; a second type conductive layerstacked on the first type conductive layer; and a light emitting layerformed between the first type conductive layer and the second typeconductive layer. The light emitting layer extends along a horizontallevel from a top edge of the first type conductive layer and from abottom edge of the second type conductive layer, such that an edge ofthe light emitting layer does not contact the top edge of the first typeconductive layer and the bottom edge of the second type conductivelayer, and the bottom edge of the second type conductive layer isaligned with the top edge of the first type conductive layer. Themicro-LED chip further includes a metal layer formed on the lightemitting layer between adjacent micro-LEDs.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layerextends along a horizontal level from a top edge of the first typeconductive layer and a bottom edge of the second type conductive layer,such that an edge of the light emitting layer does not contact the topedge of the first type conductive layer and the bottom edge of thesecond type conductive layer, and a profile of the second typeconductive layer perpendicularly projected on a top surface of the firsttype conductive layer is surrounded by an edge of the first typeconductive layer. The micro-LED chip further includes a metal layerformed on a portion of the light emitting layer that extends from thetop edge of the first type conductive layer.

According to another aspect of embodiments of the present disclosure, amicro-LED chip includes multiple micro-LEDs. At least one micro-LED ofthe multiple micro-LEDs includes: a first type conductive layer; asecond type conductive layer stacked on the first type conductive layer;and a light emitting layer formed between the first type conductivelayer and the second type conductive layer. The light emitting layerextends along a horizontal level from a top edge of the first typeconductive layer and a bottom edge of the second type conductive layer,such that an edge of the light emitting layer does not touch the topedge of the first type conductive layer and the bottom edge of thesecond type conductive layer. A profile of the first type conductivelayer perpendicularly projected on a bottom surface of the second typeconductive layer is surrounded by the bottom edge of the second typeconductive layer. The micro-LED chip further includes a metal layerformed on a portion of the light emitting layer that extends from thesecond type conductive layer.

BRIEF DESCRIPTION OF DRAWING(S)

FIG. 1A is a cross-sectional view of a micro-LED structure, according toa first embodiment of the present disclosure.

FIG. 1B is a cross-sectional view of a micro-LED structure, according toa first variation of the first embodiment of the present disclosure.

FIG. 1C is a cross-sectional view of a micro-LED structure, according toa second variation of the first embodiment of the present disclosure.

FIG. 1D is a cross-sectional view of a micro-LED structure, according toa third variation of the first embodiment of the present disclosure.

FIG. 2A is a cross-sectional view of a micro-LED structure, according toa second embodiment of the present disclosure.

FIG. 2B is a cross-sectional view of a micro-LED structure, according toa first variation of the second embodiment of the present disclosure.

FIG. 2C is a cross-sectional view of a micro-LED structure, according toa second variation of the second embodiment of the present disclosure.

FIG. 2D is a cross-sectional view of a micro-LED structure, according toa third variation of the second embodiment of the present disclosure.

FIG. 3A is a cross-sectional view of a micro-LED structure, according toa third embodiment of the present disclosure.

FIG. 3B is a cross-sectional view of a micro-LED structure, according toa first variation of the third embodiment of the present disclosure.

FIG. 3C is a cross-sectional view of a micro-LED structure, according toa second variation of the third embodiment of the present disclosure.

FIG. 3D is a cross-sectional view of a micro-LED structure, according toa third variation of the third embodiment of the present disclosure.

FIG. 4A is a cross-sectional view of a micro-LED structure, according toa fourth embodiment of the present disclosure.

FIG. 4B is a cross-sectional view of a micro-LED structure, according toa first variation of the fourth embodiment of the present disclosure.

FIG. 4C is a cross-sectional view of a micro-LED structure, according toa second variation of the fourth embodiment of the present disclosure.

FIG. 4D is a cross-sectional view of a micro-LED structure, according toa third variation of the fourth embodiment of the present disclosure.

FIG. 5A is a cross-sectional view of a micro-LED structure, according toa fifth embodiment of the present disclosure.

FIG. 5B is a cross-sectional view of a micro-LED structure, according toa first variation of the fifth embodiment of the present disclosure.

FIG. 5C is a cross-sectional view of a micro-LED structure, according toa second variation of the fifth embodiment of the present disclosure.

FIG. 5D is a cross-sectional view of a micro-LED structure, according toa third variation of the fifth embodiment of the present disclosure.

FIG. 6A is a cross-sectional view of a micro-LED chip, according to asixth embodiment of the present disclosure.

FIG. 6B is a cross-sectional view of a micro-LED chip, according to afirst variation of the sixth embodiment of the present disclosure.

FIG. 6C is a cross-sectional view of a micro-LED chip, according to asecond variation of the sixth embodiment of the present disclosure.

FIG. 6D is a cross-sectional view of a micro-LED chip, according to athird variation of the sixth embodiment of the present disclosure.

FIG. 6E is a cross-sectional view of a micro-LED chip, according to afourth variation of the sixth embodiment of the present disclosure.

FIG. 6F is a cross-sectional view of a micro-LED chip, according to afifth variation of the sixth embodiment of the present disclosure.

FIG. 7 is a cross-sectional view of a micro-LED chip, according to aseventh embodiment of the present disclosure.

FIG. 8A is a cross-sectional view of a micro-LED chip, according to aneighth embodiment of the present disclosure.

FIG. 8B is a cross-sectional view of a micro-LED chip, according to afirst variation of the eighth embodiment of the present disclosure.

FIG. 8C is a cross-sectional view of a micro-LED chip, according to asecond variation of the eighth embodiment of the present disclosure.

FIG. 9A is a cross-sectional view of a micro-LED chip, according to aninth embodiment of the present disclosure.

FIG. 9B is a cross-sectional view of a micro-LED chip, according to afirst variation of the ninth embodiment of the present disclosure.

FIG. 9C is a cross-sectional view of a micro-LED chip, according to asecond variation of the seventh embodiment of the present disclosure.

FIG. 10A is a cross-sectional view of a micro-LED chip, according to atenth embodiment of the present disclosure.

FIG. 10B is a cross-sectional view of a micro-LED chip, according to afirst variation of the tenth embodiment of the present disclosure.

FIG. 10C is a cross-sectional view of a micro-LED chip, according to asecond variation of the tenth embodiment of the present disclosure.

FIG. 11A is a cross-sectional view of a micro-LED chip, according to aneleventh embodiment of the present disclosure.

FIG. 11B is a cross-sectional view of a micro-LED chip, according to afirst variation of the eleventh embodiment of the present disclosure.

FIG. 11C is a cross-sectional view of a micro-LED chip, according to asecond variation of the eleventh embodiment of the present disclosure.

FIG. 11D is a cross-sectional view of a micro-LED chip, according to athird variation of the eleventh embodiment of the present disclosure.

FIG. 12A is a cross-sectional view of a micro-LED chip, according to atwelfth embodiment of the present disclosure.

FIG. 12B is a cross-sectional view of a micro-LED chip, according to afirst variation of the twelfth embodiment of the present disclosure.

FIG. 12C is a cross-sectional view of a micro-LED chip, according to asecond variation of the twelfth embodiment of the present disclosure.

FIG. 12D is a cross-sectional view of a micro-LED chip, according to athird variation of the twelfth embodiment of the present disclosure.

FIG. 13A is a cross-sectional view of a micro-LED chip, according to athirteenth embodiment of the present disclosure.

FIG. 13B is a cross-sectional view of a micro-LED chip, according to avariation of the thirteenth embodiment of the present disclosure.

FIG. 14A is a cross-sectional view of a micro-LED chip, according to afourteenth embodiment of the present disclosure.

FIG. 14B is a cross-sectional view of a micro-LED chip, according to avariation of the fourteenth embodiment of the present disclosure.

FIG. 15A is a cross-sectional view of a micro-LED chip, according to afifteenth embodiment of the present disclosure.

FIG. 15B is a cross-sectional view of a micro-LED chip, according to avariation of the fifteenth embodiment of the present disclosure.

FIG. 16A is a cross-sectional view of a micro-LED chip, according to asixteenth embodiment of the present disclosure.

FIG. 16B is a cross-sectional view of a micro-LED chip, according to avariation of the sixteenth embodiment of the present disclosure.

FIG. 17A is a cross-sectional view of a micro-LED chip, according to aseventeenth embodiment of the present disclosure.

FIG. 17B is a cross-sectional view of a micro-LED chip, according to avariation of the seventeenth embodiment of the present disclosure.

FIG. 18 is a cross-sectional view of a micro-LED structure, according toa comparative example.

DETAILED DESCRIPTION

The text below provides a detailed description of the present disclosurein conjunction with specific embodiments illustrated in the attacheddrawings. However, these embodiments do not limit the presentdisclosure. The scope of protection for the present disclosure coverschanges made to the structure, method, or function by persons havingordinary skill in the art on the basis of these embodiments.

To facilitate the presentation of the drawings in the presentdisclosure, the sizes of certain structures or portions may be enlargedrelative to other structures or portions. Therefore, the drawings in thepresent application are only for the purpose of illustrating the basicstructure of the subject matter of the present application. The samenumbers in different drawings represent the same or similar elementsunless otherwise represented.

Additionally, terms in the text indicating relative spatial position,such as “front,” “back,” “upper,” “lower,” “above,” “below,” and soforth, are used for explanatory purposes in describing the relationshipbetween a unit or feature depicted in a drawing and another unit orfeature therein. Terms indicating relative spatial position may refer topositions other than those depicted in the drawings when a device isbeing used or operated. For example, if a device shown in a drawing isflipped over, a unit which is described as being positioned “below” or“under” another unit or feature will be located “above” the other unitor feature. Therefore, the illustrative term “below” may includepositions both above and below. A device may be oriented in other ways(rotated 90 degrees or facing another direction), and descriptive termsthat appear in the text and are related to space should be interpretedaccordingly. When a component or layer is said to be “above” anothermember or layer or “connected to” another member or layer, it may bedirectly above the other member or layer or directly connected to theother member or layer, or there may be an intermediate component orlayer.

First Embodiment

FIG. 1A is a cross-sectional view of a micro-light emitting diode(micro-LED) structure 1000, according to a first embodiment of thepresent disclosure. As illustrated in FIG. 1A, the micro-LED structure1000 includes a first type conductive layer 101, a second typeconductive layer 102 stacked on the first type conductive layer 101, anda light emitting layer 103 formed between the first type conductivelayer 101 and the second type conductive layer 102. The light emittinglayer 103 extends along a horizontal level away from a top edge 101 a ofthe first type conductive layer 101 and a bottom edge 102 a of thesecond type conductive layer 102, such that an edge 103 a of the lightemitting layer 103 and does not contact the top edge 101 a of the firsttype conductive layer 101 and the bottom edge 102 a of the second typeconductive layer 102. The bottom edge 102 a of the second typeconductive layer 102 is aligned with the top edge 101 a of the firsttype conductive layer 101.

The first type conductive layer 101 and the second type conductive layer102 may be any type of conductive layers. In one embodiment, the firsttype conductive layer 101 may be an n-type conductive semiconductorcontaining one or more n-type dopants, and the second type conductivelayer 102 may be a p-type conductive semiconductor layer containing oneor more p-type dopants. In another embodiment, the first type conductivelayer 101 may be a p-type conductive semiconductor, and the second typeconductive layer 102 may be an n-type conductive semiconductor layer. Asillustrated in FIG. 1A, a top area of the first type conductive layer101 is larger than a bottom area of the first type conductive layer 101.A top area of the second type conductive layer 102 is smaller than abottom area of the second type conductive layer 102.

The light emitting layer 103 may have a quantum well structure in whichquantum well layers and barrier layers are alternately stacked. In oneembodiment, the light emitting layer 103 may include one pair of quantumwell layers and a barrier layer interposed between the quantum welllayers. In another embodiment, the light emitting layer 103 may includemultiple pairs of quantum well layers and a barrier layer interposedbetween adjacent quantum well layers. The quantum well layers are madeof, for example, GaAs, AlGaAs, InGaAs, GaAsP, AlGaInP, GaInAsP, GaInP,AlInP, GaP, InP, or the like. The barrier layers are formed of, forexample, GaAs, AlGaAs, InGaAs, GaAsP, AlGaInP, GaInAsP, GaInP, AlInP,GaP, InP, or the like.

As illustrated in FIG. 1A, the micro-LED structure 1000 also includes atop spacer 107 formed on a top surface 103 b of the light emitting layer103, and a bottom spacer 108 formed on a bottom surface 103 c of thelight emitting layer 103. The top spacer 107 and the bottom spacer 108may be made of GaAs, AlGaAs, InGaAs, GaAsP, AlGaInP, GaInAsP, GaInP,AlInP, GaP, InP or the like. The top spacer 107 and the bottom spacer108 are configured to control the carrier injection efficiency toimprove the performance and reliability of the micro-LED. An edge 107 aof the top spacer 107 and an edge 108 a of the bottom spacer 108 arealigned with the edge 103 a of the light emitting layer 103. A thicknessof the top spacer 107 is larger than a thickness of the light emittinglayer 103. A thickness of the bottom spacer 108 is larger than thethickness of the light emitting layer 103.

In the embodiment illustrated in FIG. 1A, the micro-LED structure 1000further includes a reflective structure 104 surrounding the first typeconductive layer 101. The reflective structure 104 is attached on asidewall surface 101 b of the first type conductive layer 101. Thereflective structure 104 on the sidewall of the first type conductivelayer 101 is inclined relative to a surface 110 a of a substrate 110. Aninclined angle of the reflective structure 104 is approximately 30° toapproximately 75° relative to the surface 110 a of the substrate 110.The reflective structure 104 on the sidewall surface 101 b of the firsttype conductive layer 101 is made of an ODR (omnidirectional reflector)structure or a DBR (distributed bragg reflection) structure. Thereflective structure 104 is configured to focus light on the second typeconductive layer 102.

In the embodiment illustrated in FIG. 1A, the micro-LED structure 1000further includes a bottom connection structure 105 formed under thefirst type conductive layer 101, and electrically connected with thefirst type conductive layer 101. The bottom connection structure 105 maybe formed of electrically conductive material, such as, for example,metal. The bottom connection structure 105 may be reflective.

As illustrated in FIG. 1A, the micro-LED structure 1000 further includesthe substrate 110 under the first type conductive layer 101, and iselectrically connected with the bottom connection structure 105 by aconnecting pad 106 in the substrate 110. In some embodiments, thesubstrate 110 may be made of one of more of the materials from the III-Vgroups, such as, for example, GaN. In some other embodiments, thesubstrate 110 may include an IC circuit. The connecting pad 106 may bemade of conductive materials, such as, for example, Cu.

As illustrated in FIG. 1A, the micro-LED structure 1000 further includesan isolation layer 109 surrounding the first type conductive layer 101and under the light emitting layer 103. The isolation layer 109 may bemade of a light absorption material which includes, for example,impurity doped SiO₂ or Si₃N₄.

As illustrated in FIG. 1A, the micro-LED structure 1000 further includesa microlens 111 formed on the second type conductive layer 102 and on atop surface of 107 b the top spacer 107. The microlens 111 is configuredto converge light emitted by the light emitting layer 103.

First Variation of First Embodiment

FIG. 1B is a cross-sectional view of a micro-LED structure 1001,according to a first variation of the first embodiment of the presentdisclosure. The embodiment illustrated in FIG. 1B differs from theembodiment illustrated in FIG. 1A in that the sidewall surface 101 b ofthe first type conductive layer 101 is curved, and a reflectivestructure 1041 is formed on the sidewall surface 101 b of the first typeconductive layer 101 has a curved surface 104 a. Except for thereflective structure 1041, the components of the micro-LED structure1001 illustrated in FIG. 1B are the same as the components of themicro-LED structure 1000 illustrated in FIG. 1A, and therefore detaileddescriptions of these components are not repeated.

Second Variation of First Embodiment

FIG. 1C is a cross-sectional view of a micro-LED structure 1002,according to a second variation of the first embodiment of the presentdisclosure. The embodiment illustrated in FIG. 1C differs from theembodiment illustrated in FIG. 1A in that a reflective structure 1042 isattached on a bottom surface 101 c of the first type conductive layer101. The reflective structure 1042 is electrically conductive. Thebottom connection structure 105 is formed at the bottom of thereflective structure 1042, and is electrically connected with thereflective structure 1042. The reflective structure 1042 on the bottomsurface 101 c of the first type conductive layer 101 may be made ofmetal. Except for the reflective structure 1042, the components of themicro-LED structure 1002 illustrated in FIG. 1C are the same as thecomponents of the micro-LED structure 1000 illustrated in FIG. 1A, andtherefore detailed descriptions of these components are not repeated.

Third Variation of First Embodiment

FIG. 1D is a cross-sectional view of a micro-LED structure 1003,according to a third variation of the first embodiment of the presentdisclosure. The embodiment illustrated in FIG. 1D differs from theembodiment illustrated in FIG. 1A in that a reflective structure 1043 isattached on both of the sidewall surface 101 b and the bottom surface101 c of the first type conductive layer 101. The reflective structure1043 is electrically conductive. The bottom connection structure 105 isformed at the bottom of the reflective structure 1043, and iselectrically connected with the reflective structure 1043. Except forthe reflective structure 1043, the components of the micro-LED structure1003 illustrated in FIG. 1D are the same as the components of themicro-LED structure 1000 illustrated in FIG. 1A, and therefore detaileddescriptions of these components are not repeated.

Second Embodiment

FIG. 2A is a cross-sectional view of a micro-LED structure 2000,according to a second embodiment of the present disclosure. The secondembodiment illustrated in FIG. 2A differs from the first embodimentillustrated in FIG. 1A in that the bottom edge 102 a of the second typeconductive layer 102 is not aligned with the top edge 101 a of the firsttype conductive layer 101. Instead, a profile of the second typeconductive layer 102 perpendicularly projected on the top surface 101 dof the first type conductive layer 101 is surrounded by the top edge 101a of the first type conductive layer 101. The components of themicro-LED structure 2000 of the second embodiment illustrated in FIG. 2Aare the same as the components of the micro-LED structure 1000 of thefirst embodiment illustrated in FIG. 1A, and therefore detaileddescriptions of these components are not repeated.

First Variation of Second Embodiment

FIG. 2B is a cross-sectional view of a micro-LED structure 2001,according to a first variation of the second embodiment of the presentdisclosure. The embodiment illustrated in FIG. 2B differs from theembodiment illustrated in FIG. 2A in that the sidewall surface 101 b ofthe first type conductive layer 101 is curved, and the reflectivestructure 1041 is formed on the sidewall surface 101 b of the first typeconductive layer 101 has the curved surface 104 a. Except for thereflective structure 1041, the components of the micro-LED structure2001 illustrated in FIG. 2B are the same as the components of themicro-LED structure 2000 illustrated in FIG. 2A, and therefore detaileddescriptions of these components are not repeated.

Second Variation of Second Embodiment

FIG. 2C is a cross-sectional view of a micro-LED structure 2002,according to a second variation of the second embodiment of the presentdisclosure. The embodiment illustrated in FIG. 2C differs from theembodiment illustrated in FIG. 2A in that the reflective structure 1042is attached on the bottom surface 101 c of the first type conductivelayer 101. The reflective structure 1042 is electrically conductive. Thebottom connection structure 105 is formed at the bottom of thereflective structure 1042, and is electrically connected with the bottomof the reflective structure 1042. The reflective structure 1042 on thebottom surface 101 c of the first type conductive layer 101 may be madeof metal. Except for the reflective structure 1042, the components ofthe micro-LED structure 2002 illustrated in FIG. 2C are the same as thecomponents of the micro-LED structure 2000 illustrated in FIG. 2A, andtherefore detailed descriptions of these components are not repeated.

Third Variation of Second Embodiment

FIG. 2D is a cross-sectional view of a micro-LED structure 2003,according to a third variation of the second embodiment of the presentdisclosure. The embodiment illustrated in FIG. 2D differs from theembodiment illustrated in FIG. 2A in that the reflective structure 1043is attached on both of the sidewall surface 101 b and the bottom surface101 c of the first type conductive layer 101. The reflective structure1043 is electrically conductive. The bottom connection structure 105 isformed at the bottom of the reflective structure 1043, and iselectrically connected with the reflective structure 1043. Except forthe reflective structure 1043, the components of the micro-LED structure2003 illustrated in FIG. 2D are the same as the components of themicro-LED structure 2000 illustrated in FIG. 2A, and therefore detaileddescriptions of these components are not repeated.

Third Embodiment

FIG. 3A is a cross-sectional view of a micro-LED structure 3000,according to a third embodiment of the present disclosure. The thirdembodiment illustrated in FIG. 3A differs from the first embodimentillustrated in FIG. 1A in that the bottom edge 102 a of the second typeconductive layer 102 is not aligned with the top edge 101 a of the firsttype conductive layer 101. Instead, a profile of the first typeconductive layer 101 perpendicularly projected on a bottom surface 102 bof the second type conductive layer 102 is surrounded by the bottom edge102 a of the second type conductive layer 102. The components of themicro-LED structure 3000 of the third embodiment illustrated in FIG. 3Aare the same as the components of the micro-LED structure 1000 of thefirst embodiment illustrated in FIG. 1A, and therefore detaileddescriptions of these components are not repeated.

First Variation of Third Embodiment

FIG. 3B is a cross-sectional view of a micro-LED structure 3001,according to a first variation of the third embodiment of the presentdisclosure. The embodiment illustrated in FIG. 3B differs from theembodiment illustrated in FIG. 3A in that the sidewall surface 101 b ofthe first type conductive layer 101 is curved, and the reflectivestructure 1041 is formed on the sidewall surface 101 b of the first typeconductive layer 101 has the curved surface 104 a. Except for thereflective structure 104, the components of the micro-LED structure 3001illustrated in FIG. 3B are the same as the components of the micro-LEDstructure 3000 illustrated in FIG. 3A, and therefore detaileddescriptions of these components are not repeated.

Second Variation of Third Embodiment

FIG. 3C is a cross-sectional view of a micro-LED structure 3002,according to a second variation of the third embodiment of the presentdisclosure. The embodiment illustrated in FIG. 3C differs from theembodiment illustrated in FIG. 3A in that the reflective structure 1042is attached on the bottom surface 101 c of the first type conductivelayer 101. The reflective structure 1042 is electrically conductive. Thebottom connection structure 105 is formed at the bottom of thereflective structure 1042, and is electrically connected with the bottomof the reflective structure 1042. The reflective structure 1042 on thebottom surface 101 c of the first type conductive layer 101 may be madeof metal. Except for the reflective structure 1042, the components ofthe micro-LED structure 3002 illustrated in FIG. 3C are the same as thecomponents of the micro-LED structure 3000 illustrated in FIG. 3A, andtherefore detailed descriptions of these components are not repeated.

Third Variation of Third Embodiment

FIG. 3D is a cross-sectional view of a micro-LED structure 3003,according to a third variation of the third embodiment of the presentdisclosure. The embodiment illustrated in FIG. 3D differs from theembodiment illustrated in FIG. 3A in that the reflective structure 1043is attached on both of the sidewall surface 101 b and the bottom surface101 c of the first type conductive layer 101. The reflective structure1043 is electrically conductive. The bottom connection structure 105 isformed at the bottom of the reflective structure 1043, and iselectrically connected with the reflective structure 1043. Except forthe reflective structure 1042, the components of the micro-LED structure3003 illustrated in FIG. 3D are the same as the components of themicro-LED structure 3000 illustrated in FIG. 3A, and therefore detaileddescriptions of these components are not repeated.

Fourth Embodiment

FIG. 4A is a cross-sectional view of a micro-LED structure 4000,according to a fourth embodiment of the present disclosure. The fourthembodiment illustrated in FIG. 4A differs from the third embodimentillustrated in FIG. 3A in that the light emitting layer 103 extendsalong a horizontal level away from the top edge 101 a of the first typeconductive layer 101, and the edge 103 a of the light emitting layer 103is aligned with the bottom edge 102 a of the second type conductivelayer 102. In addition, the micro-LED structure 4000 further includes atop isolation layer 114 surrounding the light emitting layer 103. Thetop isolation layer 114 may be made of one or more electrical insulatingdielectric materials, such as, for example, SiO₂, Si₃N₄, Al₂O₃, TiO₂,HfO₂, AlN or the like. The top isolation layer 114 is configured toisolate the micro-LED structure 4000 from an adjacent micro-LEDstructure (not shown). The microlens 111 is formed on the second typeconductive layer 102 and on a top surface 114 a of the isolation layer114. The other components of the micro-LED structure 4000 of the fourthembodiment illustrated in FIG. 4A are the same as the components of themicro-LED structure 3000 of the first embodiment illustrated in FIG. 3A,and therefore detailed descriptions of these components are notrepeated.

First Variation of Fourth Embodiment

FIG. 4B is a cross-sectional view of a micro-LED structure 4001,according to a first variation of the fourth embodiment of the presentdisclosure. The embodiment illustrated in FIG. 4B differs from theembodiment illustrated in FIG. 4A in that the sidewall surface 101 b ofthe first type conductive layer 101 is curved, and the reflectivestructure 1041 is formed on the sidewall surface 101 b of the first typeconductive layer 101 and has the curved surface 104 a. Except for thereflective structure 1041, the components of the micro-LED structure4001 illustrated in FIG. 4B are the same as the components of themicro-LED structure 4000 illustrated in FIG. 4A, and therefore detaileddescriptions of these components are not repeated.

Second Variation of Fourth Embodiment

FIG. 4C is a cross-sectional view of a micro-LED structure 4002,according to a second variation of the fourth embodiment of the presentdisclosure. The embodiment illustrated in FIG. 4C differs from theembodiment illustrated in FIG. 4A in that the reflective structure 1042is attached on the bottom surface 101 c of the first type conductivelayer 101. The reflective structure 1042 is electrically conductive. Thebottom connection structure 105 is formed at the bottom of thereflective structure 1042, and is electrically connected with the bottomof the reflective structure 1042. The reflective structure 1042 on thebottom surface 101 c of the first type conductive layer 101 may be madeof metal. Except for the reflective structure 1042, the components ofthe micro-LED structure 4002 illustrated in FIG. 4C are the same as thecomponents of the micro-LED structure 4000 illustrated in FIG. 4A, andtherefore detailed descriptions of these components are not repeated.

Third Variation of Fourth Embodiment

FIG. 4D is a cross-sectional view of a micro-LED structure 4003,according to a third variation of the fourth embodiment of the presentdisclosure. The embodiment illustrated in FIG. 4D differs from theembodiment illustrated in FIG. 4A in that the reflective structure 1043is attached on both of the sidewall surface 101 b and the bottom surface101 c of the first type conductive layer 101. The reflective structure1043 is electrically conductive. The bottom connection structure 105 isformed at the bottom of the reflective structure 1043, and iselectrically connected with the reflective structure 1043. Except forthe reflective structure 1042, the components of the micro-LED structure4003 illustrated in FIG. 4D are the same as the components of themicro-LED structure 4000 illustrated in FIG. 4A, and therefore detaileddescriptions of these components are not repeated.

Fifth Embodiment

FIG. 5A is a cross-sectional view of a micro-LED structure 5000,according to a fifth embodiment of the present disclosure. The fifthembodiment illustrated in FIG. 5A differs from the second embodimentillustrated in FIG. 2A in that the light emitting layer 103 extendsalong a horizontal level from the bottom edge 102 a of the second typeconductive layer 102, and the edge 103 a of the light emitting layer 103is aligned with the top edge 101 a of the first type conductive layer101. In addition, the micro-LED structure 4000 further includes the topisolation layer 114 surrounding the light emitting layer 103. Themicrolens 111 is formed on the second type conductive layer 102 and onthe top surface 114 a of the isolation layer 114. The other componentsof the micro-LED structure 5000 of the fourth embodiment illustrated inFIG. 5A are the same as the components of the micro-LED structure 2000of the second embodiment illustrated in FIG. 2A, and therefore detaileddescriptions of these components are not repeated.

First Variation of Fifth Embodiment

FIG. 5B is a cross-sectional view of a micro-LED structure 5001,according to a first variation of the fifth embodiment of the presentdisclosure. The embodiment illustrated in FIG. 5B differs from theembodiment illustrated in FIG. 5A in that the sidewall surface 101 b ofthe first type conductive layer 101 is curved, and the reflectivestructure 1041 formed on the sidewall surface 101 b of the first typeconductive layer 101 has the curved surface 104 a. Except for thereflective structure 1041, the components of the micro-LED structure5001 illustrated in FIG. 5B are the same as the components of themicro-LED structure 5000 illustrated in FIG. 5A, and therefore detaileddescriptions of these components are not repeated.

Second Variation of Fifth Embodiment

FIG. 5C is a cross-sectional view of a micro-LED structure 5002,according to a second variation of the fifth embodiment of the presentdisclosure. The embodiment illustrated in FIG. 5C differs from theembodiment illustrated in FIG. 5A in that the reflective structure 1042is attached on the bottom surface 101 c of the first type conductivelayer 101. The reflective structure 1042 is electrically conductive. Thebottom connection structure 105 is formed at the bottom of thereflective structure 1042, and is electrically connected with the bottomof the reflective structure 1042. The reflective structure 1042 on thebottom surface 101 c of the first type conductive layer 101 is made ofmetal. Except for the reflective structure 1042, the components of themicro-LED structure 5002 illustrated in FIG. 5C are the same as thecomponents of the micro-LED structure 5000 illustrated in FIG. 5A, andtherefore detailed descriptions of these components are not repeated.

Third Variation of Fifth Embodiment

FIG. 5D is a cross-sectional view of a micro-LED structure 5003,according to a third variation of the fifth embodiment of the presentdisclosure. The embodiment illustrated in FIG. 5D differs from theembodiment illustrated in FIG. 5A in that the reflective structure 1043is attached both on the sidewall surface 101 b and the bottom surface101 c of the first type conductive layer 101. The reflective structure1043 is electrically conductive. The bottom connection structure 105 isformed at the bottom of the reflective structure 1043, and iselectrically connected with the reflective structure 1043. Except forthe reflective structure 1042, the components of the micro-LED structure5003 illustrated in FIG. 5D are the same as the components of themicro-LED structure 5000 illustrated in FIG. 5A, and therefore detaileddescriptions of these components are not repeated.

Sixth Embodiment

FIG. 6A is a cross-sectional view of a micro-LED chip 6000, according toa sixth embodiment of the present disclosure. The micro-LED chip 6000may include multiple micro-LEDs. At least one of the micro-LEDs includedin the micro-LED chip 6000 may have any one of the micro-LED structures1000, 1001, . . . 3003 described above.

In the embodiment illustrated in FIG. 6A, the micro-LED chip 6000includes two micro-LEDs 610 and 620. Each one of the micro-LEDs 610 and620 includes the micro-LED structure 1000 described in the firstembodiment illustrated in FIG. 1A. Hereinafter in the description and inFIG. 6A, the micro-LEDs 610 and 620 in FIG. 6A are also referred to asmicro-LEDs 610(1000) and 620(1000).

As illustrated in FIG. 6A, each one of the micro-LEDs 610(1000) and620(1000) includes the first type conductive layer 101, the second typeconductive layer 102 stacked on the first type conductive layer 101, andthe light emitting layer 103 formed between the first type conductivelayer 101 and the second type conductive layer 102. The light emittinglayer 103 is continuously formed on the whole micro-LED chip 6000. Thefirst and second micro-LEDs 610(1000) and 620(1000) share the lightemitting layer 103. The light emitting layer 103 extends along ahorizontal level away from the top edge 101 a of the first typeconductive layer 101 and the bottom edge 102 a of the second typeconductive layer 102, such that the edge 103 a of the light emittinglayer 103 does not contact the top edge 101 a of the first typeconductive layer 101 and the bottom edge 102 a of the second typeconductive layer 102. The bottom edge 102 a of the second typeconductive layer 102 is aligned with the top edge 101 a of the firsttype conductive layer 101.

As illustrated in FIG. 6A, each one of the micro-LEDs 610(1000) and620(1000) also includes the top spacer 107 formed on the top surface 103b of the light emitting layer 103, and the bottom spacer 108 formed onthe bottom surface 103 c of the light emitting layer 103. Both of thetop spacer 107 and the bottom spacer 108 are continuously formed on thewhole micro-LED chip 6000, and are shared by the first and secondmicro-LEDs 610(1000) and 620(1000). The edge 107 a of the top spacer 107is aligned with the edge 103 a of the light emitting layer 103. The edge108 a of the bottom spacer 108 is aligned with the edge 103 a of thelight emitting layer 103.

As illustrated in FIG. 6A, each one of the micro-LEDs 610(1000) and620(1000) also includes the reflective structure 104 surrounding thefirst type conductive layer 101, the bottom connection structure 105formed under the first type conductive layer 101, the connecting pad 106formed in the substrate 110, the isolation layer 109 surrounding thefirst type conductive layer 101 and under the light emitting layer 103,the substrate 110 under the first type conductive layer 101 andelectrically connected with the bottom connection structure 105 by theconnecting pad 106, and the microlens 111 formed on the second typeconductive layer 102 and on the top surface of 107 b the top spacer 107.

Except for the light emitting layer 103, the top spacer 107, and thebottom spacer 108 that are continuously formed on the whole micro-LEDchip 6000 and are shared by the first and second micro-LEDs 610(1000)and 620(1000), the components of the first and second micro-LEDs610(1000) and 620(1000) of the sixth embodiment illustrated in FIG. 6Aare the same as the components of the micro-LED structure 1000 of thefirst embodiment illustrated in FIG. 1A. Therefore, detaileddescriptions of these components are not repeated.

First Variation of Sixth Embodiment

FIG. 6B is a cross-sectional view of a micro-LED chip 6001, according toa first variation of the sixth embodiment of the present disclosure. Thefirst variation of the sixth embodiment illustrated in FIG. 6B differsfrom the sixth embodiment illustrated in FIG. 6A in that each one of themicro-LEDs 610 and 620 in the micro-LED chip 6001 includes the micro-LEDstructure 1001 described in the first variation of the first embodimentillustrated in FIG. 1B. Therefore, the micro-LEDs 610 and 620 in FIG. 6Bare also referred to as micro-LEDs 610(1001) and 620(1001).

More specifically, as illustrated in FIG. 6B, the sidewall surface 101 bof the first type conductive layer 101 is curved, and the reflectivestructure 1041 formed on the sidewall surface 101 b of the first typeconductive layer 101 has the curved surface 104 a. Except for thereflective structure 1041, the components of the micro-LED chip 6001illustrated in FIG. 6B are the same as the components of the micro-LEDchip 6000 illustrated in FIG. 6A, and therefore detailed descriptions ofthese components are not repeated.

Second Variation of Sixth Embodiment

FIG. 6C is a cross-sectional view of a micro-LED chip 6002, according toa second variation of the sixth embodiment of the present disclosure.The second variation of the sixth embodiment illustrated in FIG. 6Cdiffers from the sixth embodiment illustrated in FIG. 6A in that eachone of the micro-LEDs 610 and 620 in the micro-LED chip 6002 includesthe micro-LED structure 1002 described in the second variation of thefirst embodiment illustrated in FIG. 1C. Therefore, the micro-LEDs 610and 620 in FIG. 6C are referred to as micro-LEDs 610(1002) and620(1002).

More specifically, as illustrated in FIG. 6C, the reflective structure1042 is attached on the bottom surface 101 c of the first typeconductive layer 101. The reflective structure 1042 is electricallyconductive. The bottom connection structure 105 is formed at the bottomof the reflective structure 1042, and is electrically connected with thebottom of the reflective structure 1042. The reflective structure 1042on the bottom surface 101 c of the first type conductive layer 01 may bemade of metal. Except for the reflective structure 1042, the componentsof the micro-LED chip 6002 illustrated in FIG. 6C are the same as thecomponents of the micro-LED chip 6000 illustrated in FIG. 6A, andtherefore detailed descriptions of these components are not repeated.

Third Variation of Sixth Embodiment

FIG. 6D is a cross-sectional view of a micro-LED chip 6003, according toa third variation of the sixth embodiment of the present disclosure. Theembodiment illustrated in FIG. 6D differs from the embodimentillustrated in FIG. 6A in that each one of the micro-LEDs 610 and 620 inthe micro-LED chip 6003 includes the micro-LED structure 1003 describedin the third variation of the first embodiment illustrated in FIG. 1D.Therefore, the micro-LEDs 610 and 620 in FIG. 6C are referred to asmicro-LEDs 610(1003) and 620(1003).

More specifically, as illustrated in FIG. 6D, the reflective structure1043 is attached both on the sidewall surface 101 b and the bottomsurface 101 c of the first type conductive layer 101. The reflectivestructure 1043 is electrically conductive. The bottom connectionstructure 105 is formed at the bottom of the reflective structure 1043,and is electrically connected with the reflective structure 1043. Exceptfor the reflective structure 1043, the components of the micro-LED chip6003 illustrated in FIG. 6D are the same as the components of themicro-LED chip 6000 illustrated in FIG. 6A, and therefore detaileddescriptions of these components are not repeated.

Fourth Variation of Sixth Embodiment

FIG. 6E is a cross-sectional view of a micro-LED chip 6004, according toa fourth variation of the sixth embodiment of the present disclosure.The embodiment illustrated in FIG. 6E differs from the embodimentillustrated in FIG. 6A in that each one of the micro-LEDs 610 and 620 inthe micro-LED chip 6004 includes the micro-LED structure 2000 describedin the second embodiment illustrated in FIG. 2A. Therefore, themicro-LEDs 610 and 620 in FIG. 6E are referred to as micro-LEDs610(2000) and 620(2000).

More specifically, as illustrated in FIG. 6E, the bottom edge 102 a ofthe second type conductive layer 102 is not aligned with the top edge101 a of the first type conductive layer 101. Instead, a profile of thesecond type conductive layer 102 perpendicularly projected on the topsurface 101 d of the first type conductive layer 101 is surrounded bythe top edge 101 a of the first type conductive layer 101. Thecomponents of the micro-LED chip 6004 of the embodiment illustrated inFIG. 6E are the same as the components of the micro-LED chip 6000 of theembodiment illustrated in FIG. 6A, and therefore detailed descriptionsof these components are not repeated.

In the embodiment illustrated in FIG. 6E, each of the micro-LEDs 610 and620 in the micro-LED chip 6004 includes the micro-LED structure 2000described in the second embodiment illustrated in FIG. 2A.Alternatively, in other embodiments, each of the micro-LEDs 610 and 620in the micro-LED chip 6004 may include the micro-LED structure 2001,2002, or 2003 described in the first, second, or third variation of thesecond embodiment illustrated in FIG. 2B, 2C, or 2D, respectively.

Fifth Variation of Sixth Embodiment

FIG. 6F is a cross-sectional view of a micro-LED chip 6005, according toa fifth variation of the sixth embodiment of the present disclosure. Theembodiment illustrated in FIG. 6F differs from the embodimentillustrated in FIG. 6A in that each one of the micro-LEDs 610 and 620 inthe micro-LED chip 6005 includes the micro-LED structure 3000 describedin the second embodiment illustrated in FIG. 3A. Therefore, themicro-LEDs 610 and 620 in FIG. 6F are referred to as micro-LEDs610(3000) and 620(3000).

More specifically, as illustrated in FIG. 6F, the bottom edge 102 a ofthe second type conductive layer 102 is not aligned with the top edge101 a of the first type conductive layer 101. Instead, a profile of thefirst type conductive layer 101 perpendicularly projected on the bottomsurface 102 b of the second type conductive layer 102 is surrounded bythe bottom edge 102 a of the second type conductive layer 102. Thecomponents of the micro-LED chip 6005 of the embodiment illustrated inFIG. 6F are the same as the components of micro-LED chip 6000 of theembodiment illustrated in FIG. 6A, and therefore detailed descriptionsof these components are not repeated.

In the embodiment illustrated in FIG. 6F, each of the micro-LEDs 610 and620 in the micro-LED chip 6005 includes the micro-LED structure 3000described in the third embodiment illustrated in FIG. 3A. Alternatively,in other embodiments, each of the micro-LEDs 610 and 620 in themicro-LED chip 6005 may include the micro-LED structure 3001, 3002, or3003 described in the first, second, or third variation of the thirdembodiment illustrated in FIG. 3B, 3C, or 3D, respectively.

Seventh Embodiment

FIG. 7 is a cross-sectional view of a micro-LED chip 7000, according toa seventh embodiment of the present disclosure. The micro-LED chip 7000may include multiple micro-LEDs. At least one of the micro-LEDs includedin the micro-LED chip 7000 may have any one of the micro-LED structures1000, 1001, . . . 3003 described above.

The micro-LED chip 7000 illustrated in FIG. 7 differs from the micro-LEDchip 6000 illustrated in FIG. 6A in that the micro-LED chip 7000 furtherincludes an isolation structure 112 formed between adjacent micro-LEDs610(1000) and 620(1000). The isolation structure 112 may be made of alight absorption material, which may be a dielectric material including,for example, impurity doped SiO₂ or Si₃N₄. In other embodiments, theisolation structure 112 may be made of a reflective material such as,for example, metal. The isolation structure 112 is configured toelectrically isolate the adjacent micro-LEDs 610(1000) and 620(1000)from each other.

At least a portion of the isolation structure 112 is formed in the lightemitting layer 103. In the embodiment illustrated in FIG. 7, a topsurface 112 a of the isolation structure 112 is aligned with the topsurface 103 b of the light emitting layer 103, and a bottom surface 112b of the isolation structure 112 is aligned with the bottom surface 103c of the light emitting layer 103. The isolation structure 112 may beformed surrounding at least one of the micro-LEDs 610(1000) and620(1000). Additionally or alternatively, at least a portion of theisolation structure 112 may be formed in the top spacer 107 or thebottom spacer 108.

Except for the isolation structure, the components of the micro-LED chip7000 of the embodiment illustrated in FIG. 7 are the same as thecomponents of the micro-LED chip 6000 of the embodiment illustrated inFIG. 6A, and therefore detailed descriptions of these components are notrepeated.

Eighth Embodiment

FIG. 8A is a cross-sectional view of a micro-LED chip 8000, according toan eighth embodiment of the present disclosure. The micro-LED chip 8000illustrated in FIG. 8A differs from the micro-LED chip 7000 illustratedin FIG. 7 in that the bottom surface 112 b of the isolation structure112 is below the light emitting layer 103. More specifically, asillustrated in FIG. 8A, the bottom surface 112 b of the isolationstructure 112 is below the bottom surface 103 c of the light emittinglayer 103 and above the bottom surface 108 b of the bottom spacer 108.Except for the isolation structure 112, the components of the micro-LEDchip 8000 illustrated in FIG. 8A are the same as the components of themicro-LED chip 7000 illustrated in FIG. 7, and therefore detaileddescriptions of these components are not repeated.

First Variation of Eighth Embodiment

FIG. 8B is a cross-sectional view of a micro-LED chip 8001, according toa first variation of the eighth embodiment of the present disclosure.The micro-LED chip 8001 illustrated in FIG. 8B differs from themicro-LED chip 8000 illustrated in FIG. 8A in that the bottom surface112 b of the isolation structure 112 is aligned with the bottom surface108 b of the bottom spacer 108. Except for the isolation structure 112,the components of the micro-LED chip 8001 illustrated in FIG. 8B are thesame as the components of the micro-LED chip 8000 illustrated in FIG.8A, and therefore detailed descriptions of these components are notrepeated.

Second Variation of Eighth Embodiment

FIG. 8C is a cross-sectional view of a micro-LED chip 8002, according toa second variation of the eighth embodiment of the present disclosure.The micro-LED chip 8002 illustrated in FIG. 8C differs from themicro-LED chip 8000 illustrated in FIG. 8A in that the bottom surface112 b of the isolation structure 112 is below the bottom surface 108 bof the bottom spacer 108 and is disposed in the isolation layer 109.Except for the isolation structure 112, the components of the micro-LEDchip 8002 illustrated in FIG. 8C are the same as the components of themicro-LED chip 8000 illustrated in FIG. 8A, and therefore detaileddescriptions of these components are not repeated.

In the embodiments illustrated in FIGS. 8A-8C, an area of the topsurface 112 a of the isolation structure 112 is equal to an area of thebottom surface 112 b of the isolation structure 112. Alternatively, inother embodiments, the area of the top surface 112 a of the isolationstructure 112 may be larger or smaller than the area of the bottomsurface 112 b of the isolation structure 112. Still alternatively, insome embodiments, a cross-sectional area of the isolation structure 112at an interface between the light emitting layer 103 and the bottomspacer 108, or at the bottom surface 108 b of the bottom spacer 108, maybe larger than the area of the bottom surface 112 b of the isolationstructure 112.

Ninth Embodiment

FIG. 9A is a cross-sectional view of a micro-LED chip 9000, according toa ninth embodiment of the present disclosure. The micro-LED chip 9000illustrated in FIG. 9A differs from the micro-LED chip 7000 illustratedin FIG. 7 in that the top surface 112 a of the isolation structure 112is above the light emitting layer 103. More specifically, as illustratedin FIG. 9A, the top surface 112 a of the isolation structure 112 isabove the top surface 103 b of the light emitting layer 103 and belowthe top surface 107 b of the top spacer 107. Except for the isolationstructure 112, the components of the micro-LED chip 9000 illustrated inFIG. 9A are the same as the components of the micro-LED chip 7000illustrated in FIG. 7, and therefore detailed descriptions of thesecomponents are not repeated.

First Variation of Ninth Embodiment

FIG. 9B is a cross-sectional view of a micro-LED chip 9001, according toa first variation of the ninth embodiment of the present disclosure. Themicro-LED chip 9001 illustrated in FIG. 9B differs from the micro-LEDchip 9000 illustrated in FIG. 9A in that the top surface 112 a of theisolation structure 112 is aligned with the top surface 107 b of the topspacer 107. Except for the isolation structure 112, the components ofthe micro-LED chip 9001 illustrated in FIG. 9B are the same as thecomponents of the micro-LED chip 9000 illustrated in FIG. 9A, andtherefore detailed descriptions of these components are not repeated.

Second Variation of Ninth Embodiment

FIG. 9C is a cross-sectional view of a micro-LED chip 9002, according toa second variation of the ninth embodiment of the present disclosure.The micro-LED chip 9002 illustrated in FIG. 9C differs from themicro-LED chip 9000 illustrated in FIG. 9A in that the top surface 112 aof the isolation structure 112 is above the top surface 107 b of the topspacer 107 and between adjacent second type conductive layers 102.Except for the isolation structure 112, the components of the micro-LEDchip 9002 illustrated in FIG. 9C are the same as the components of themicro-LED chip 9000 illustrated in FIG. 9A, and therefore detaileddescriptions of these components are not repeated.

In the embodiment illustrated in FIGS. 9A-9C, the area of the topsurface 112 a of the isolation structure 112 is equal to the area of thebottom surface 112 b of the isolation structure 112. Alternatively, inother embodiments, the area of the top surface 112 a of the isolationstructure 112 may be larger or smaller than the area of the bottomsurface 112 b of the isolation structure 112. Still alternatively, insome embodiments, a cross-sectional area of the isolation structure 112at the top surface 103 b of the light emitting layer 103 or at the topsurface 107 b of the top spacer 107 may be larger than the area of thebottom surface 112 b of the isolation structure 112.

Tenth Embodiment

FIG. 10A is a cross-sectional view of a micro-LED chip 10000, accordingto a tenth embodiment of the present disclosure. The micro-LED chip10000 illustrated in FIG. 10A differs from the micro-LED chip 7000illustrated in FIG. 7 in that the top surface 112 a of the isolationstructure 112 is above the light emitting layer 103, and the bottomsurface 112 b of the isolation structure 112 is below the light emittinglayer 103. More specifically, as illustrated in FIG. 10A, the topsurface 112 a of the isolation structure 112 is above the top surface103 b of the light emitting layer 103 and below the top surface 107 b ofthe top spacer 107, and the bottom surface 112 b of the isolationstructure 112 is below the bottom surface 103 c of the light emittinglayer 103 and above the bottom surface 108 b of the bottom spacer 108.Except for the isolation structure 112, the components of the micro-LEDchip 10000 illustrated in FIG. 10A are the same as the components of themicro-LED chip 7000 illustrated in FIG. 7, and therefore detaileddescriptions of these components are not repeated.

First Variation of Tenth Embodiment

FIG. 10B is a cross-sectional view of a micro-LED chip 10001, accordingto a first variation of the tenth embodiment of the present disclosure.The micro-LED chip 10001 illustrated in FIG. 10B differs from themicro-LED chip 10000 illustrated in FIG. 10A in that the bottom surface112 b of the isolation structure 112 is aligned with the bottom surface108 b of the bottom spacer 108. Except for the isolation structure 112,the components of the micro-LED chip 10001 illustrated in FIG. 10B arethe same as the components of the micro-LED chip 10000 illustrated inFIG. 10A, and therefore detailed descriptions of these components arenot repeated.

Second Variation of Tenth Embodiment

FIG. 10C is a cross-sectional view of a micro-LED chip 10002, accordingto a second variation of the tenth embodiment of the present disclosure.The micro-LED chip 10002 illustrated in FIG. 10C differs from themicro-LED chip 10000 illustrated in FIG. 10A in that the bottom surface112 b of the isolation structure 112 is below the bottom surface 108 bof the bottom spacer 108 and is disposed in the isolation layer 109.Except for the isolation structure 112, the components of the micro-LEDchip 10002 illustrated in FIG. 10C are the same as the components of themicro-LED chip 10000 illustrated in FIG. 10A, and therefore detaileddescriptions of these components are not repeated.

In the embodiment illustrated in FIGS. 10A-10C, the area of the topsurface 112 a of the isolation structure 112 is equal to the area of thebottom surface 112 b of the isolation structure 112. Alternatively, inother embodiments, the area of the top surface 112 a of the isolationstructure 112 may be larger or smaller than the area of the bottomsurface 112 b of the isolation structure 112. Still alternatively, insome embodiments, a cross-sectional area of the isolation structure 112at the bottom surface 103 c of the light emitting layer 103 or at thebottom surface 108 b of the bottom spacer 108 may be larger than thearea of the bottom surface 112 b of the isolation structure 112.

Eleventh Embodiment

FIG. 11A is a cross-sectional view of a micro-LED chip 11000, accordingto an eleventh embodiment of the present disclosure. The micro-LED chip11000 illustrated in FIG. 11A differs from the micro-LED chip 7000illustrated in FIG. 7 in that the top surface 112 a of the isolationstructure 112 is aligned with the top surface 107 b of the top spacer107, and the bottom surface 112 b of the isolation structure 112 isbelow the light emitting layer 103. More specifically, in the embodimentillustrated in FIG. 11A, the bottom surface 112 b of the isolationstructure 112 is below the bottom surface 103 c of the light emittinglayer 103 and above the bottom surface 108 b of the bottom spacer 108.Except for the isolation structure 112, the components of the micro-LEDchip 11000 illustrated in FIG. 11A are the same as the components of themicro-LED chip 7000 illustrated in FIG. 7, and therefore detaileddescriptions of these components are not repeated.

First Variation of Eleventh Embodiment

FIG. 11B is a cross-sectional view of a micro-LED chip 11001, accordingto a first variation of the eleventh embodiment of the presentdisclosure. The micro-LED chip 11001 illustrated in FIG. 11B differsfrom the micro-LED chip 11000 illustrated in FIG. 11A in that the bottomsurface 112 b of the isolation structure 112 is aligned with the bottomsurface 108 b of the bottom spacer 108. Except for the isolationstructure 112, the components of the micro-LED chip 11001 illustrated inFIG. 11A are the same as the components of the micro-LED chip 11000illustrated in FIG. 11A, and therefore detailed descriptions of thesecomponents are not repeated.

Second Variation of Eleventh Embodiment

FIG. 11C is a cross-sectional view of a micro-LED chip 11002, accordingto a second variation of the eleventh embodiment of the presentdisclosure. The micro-LED chip 11002 illustrated in FIG. 11C differsfrom the micro-LED chip 11000 illustrated in FIG. 11A in that the bottomsurface 112 b of the isolation structure 112 is below the bottom surface108 b of the bottom spacer 108 and is disposed in the isolation layer109. Except for the isolation structure 112, the components of themicro-LED chip 11002 illustrated in FIG. 11C are the same as thecomponents of the micro-LED chip 11000 illustrated in FIG. 11A, andtherefore detailed descriptions of these components are not repeated.

In the embodiment illustrated in FIGS. 11A-11C, the area of the topsurface 112 a of the isolation structure 112 is equal to the area of thebottom surface 112 b of the isolation structure 112. Alternatively, inother embodiments, the area of the top surface 112 a of the isolationstructure 112 may be larger or smaller than the area of the bottomsurface 112 b of the isolation structure 112. Still alternatively, insome embodiments, a cross-sectional area of the isolation structure 112at the bottom surface 103 c of the light emitting layer 103 or thebottom surface 108 b of the bottom spacer 108 may be larger than thearea of the bottom surface 112 b of the isolation structure 112.

Third Variation of Eleventh Embodiment

FIG. 11D is a cross-sectional view of a micro-LED chip 11003, accordingto a third variation of the eleventh embodiment of the presentdisclosure. The micro-LED chip 11003 illustrated in FIG. 11D differsfrom the micro-LED chip 11001 illustrated in FIG. 11B in that the areaof the top surface 112 a of the isolation structure 112 is larger thanan area of the bottom surface 112 b of the isolation structure 112.Except for the isolation structure 112, the components of the micro-LEDchip 11003 illustrated in FIG. 11D are the same as the components of themicro-LED chip 11001 illustrated in FIG. 11B, and therefore detaileddescriptions of these components are not repeated.

Twelfth Embodiment

FIG. 12A is a cross-sectional view of a micro-LED chip 12000, accordingto a twelfth embodiment of the present disclosure. The micro-LED chip12000 illustrated in FIG. 12A differs from the micro-LED chip 7000illustrated in FIG. 7 in that the top surface 112 a of the isolationstructure 112 is above the top surface 107 b of the top spacer 107 andbetween adjacent second type conductive layers 102, and the bottomsurface 112 b of the isolation structure 112 is below the light emittinglayer 103. More specifically, in the embodiment illustrated in FIG. 12A,the bottom surface 112 b of the isolation structure 112 is below thebottom surface 103 c of the light emitting layer 103 and above thebottom surface 108 b of the bottom spacer 108. Except for the isolationstructure 112, the components of the micro-LED chip 12000 illustrated inFIG. 12A are the same as the components of the micro-LED chip 7000illustrated in FIG. 7, and therefore detailed descriptions of thesecomponents are not repeated.

First Variation of Twelfth Embodiment

FIG. 12B is a cross-sectional view of a micro-LED chip 12001, accordingto a first variation of the twelfth embodiment of the presentdisclosure. The micro-LED chip 12001 illustrated in FIG. 12B differsfrom the micro-LED chip 12000 illustrated in FIG. 12A in that the bottomsurface 112 b of the isolation structure 112 is aligned with the bottomsurface 108 b of the bottom spacer 108. Except for the isolationstructure 112, the components of the micro-LED chip 12001 illustrated inFIG. 12B are the same as the components of the micro-LED chip 12000illustrated in FIG. 12A, and therefore detailed descriptions of thesecomponents are not repeated.

Second Variation of Twelfth Embodiment

FIG. 12C is a cross-sectional view of a micro-LED chip 12002, accordingto a second variation of the twelfth embodiment of the presentdisclosure. The micro-LED chip 12002 illustrated in FIG. 12C differsfrom the micro-LED chip 12000 illustrated in FIG. 12A in that the bottomsurface 112 b of the isolation structure 112 is below the bottom surface108 b of the bottom spacer 108 and disposed in the isolation layer 109.Except for the isolation structure 112, the components of the micro-LEDchip 12002 illustrated in FIG. 12C are the same as the components of themicro-LED chip 12000 illustrated in FIG. 12A, and therefore detaileddescriptions of these components are not repeated.

Third Variation of Twelfth Embodiment

FIG. 12D is a cross-sectional view of a micro-LED chip 12003, accordingto a third variation of the twelfth embodiment of the presentdisclosure. The micro-LED chip 12003 illustrated in FIG. 12D differsfrom the micro-LED chip 12002 illustrated in FIG. 12C in that the areaof the top surface 112 a of the isolation structure 112 is smaller thanthe area of the bottom surface 112 b of the isolation structure 112, anda cross-sectional area 112 c of the isolation structure 112 at thebottom surface 103 c of the light emitting layer 103 is larger than thearea of the bottom surface 112 b of the isolation structure 112. Exceptfor the isolation structure 112, the components of the micro-LED chip12003 illustrated in FIG. 12D are the same as the components of themicro-LED chip 12002 illustrated in FIG. 12C, and therefore detaileddescriptions of these components are not repeated.

Thirteenth Embodiment

FIG. 13A is a cross-sectional view of a micro-LED chip 13000, accordingto a thirteenth embodiment of the present disclosure. The micro-LED chip13000 may include multiple micro-LEDs. At least one of the micro-LEDsincluded in the micro-LED chip 13000 may have any one of the micro-LEDstructures 1000, 1001, . . . 3003 described above.

The micro-LED chip 13000 illustrated in FIG. 13A differs from themicro-LED chip 6000 illustrated in FIG. 6A in that the micro-LED chip13000 further includes a metal layer 113 formed over the light emittinglayer 103 between adjacent micro-LEDs 610(1000) and 620(1000). The metallayer 113 is formed over the top surface 103 b of the light emittinglayer 103 and does not contact the first type conductive layer 101 orthe second type conductive layer 102. More specifically, in theembodiment illustrated in FIG. 13A, the top spacer 107 is formed on topof the light emitting layer 103, and the metal layer 113 is formed onthe top surface 107 b of the top spacer 107.

A lateral dimensional value d1 of the metal layer 113 is not more than adistance d2 between the edge 103 a of the light emitting layer 103 andthe top edge 101 a of the first type conductive layer 101, or thelateral dimensional value d1 of the metal layer 113 is not more than adistance d3 between the edge 103 a of the light emitting layer 103 andthe bottom edge 102 a of the second type conductive layer 102. Thelateral dimensional value d1 of the metal layer 113 may be fromapproximately 2 nm to approximately 10 um.

In some embodiments, a center point of the metal layer 113 may bealigned with a center point between the adjacent micro-LEDs 610(1000)and 620(1000). Alternatively, in some embodiments, the center point ofthe metal layer 113 is closer to one of the adjacent micro-LEDs610(1000) and 620(1000) than the other one of the micro-LEDs 610(1000)and 620(1000).

The metal layer 113 may include a high work function metal materialhaving a work function that matches the work function of a material ofthe light emitting layer 103. The high work function metal material mayinclude at least one of gold, platinum, palladium, beryllium, cobalt,nickel, or tungsten.

Variation of Thirteenth Embodiment

FIG. 13B is a cross-sectional view of a micro-LED chip 13001, accordingto a variation of the thirteenth embodiment of the present disclosure.The micro-LED chip 13001 illustrated in FIG. 13B differs from themicro-LED chip 13000 illustrated in FIG. 13A in that the micro-LED chip13001 includes multiple metal layers 113 formed on the top surface 107 bof the top spacer 107 and between adjacent micro-LEDs 610(1000) and620(1000). The metal layers 113 are arranged in parallel along the topsurface 103 b of the light emitting layer 103.

In the embodiment illustrated in FIG. 13B, there are three (3) metallayers 113. In other embodiments, the number of the metal layers 113 maybe more than three.

In the embodiments illustrated in FIGS. 13A and 13B, each of themicro-LEDs 610 and 620 includes the micro-LED structure 1000 describedin the first embodiment illustrated in FIG. 1A. Alternatively, in otherembodiments, each of the micro-LEDs 610 and 620 may include any one ofthe micro-LED structures 1001, 1002, and 1003 described in the first,second, and third variations of the first embodiment illustrated inFIGS. 1B, 1C, and 1D, respectively.

Fourteenth Embodiment

FIG. 14A is a cross-sectional view of a micro-LED chip 14000, accordingto a fourteenth embodiment of the present disclosure. The embodimentillustrated in FIG. 14A differs from the embodiment illustrated in FIG.13A in that micro-LED chip 14000 includes two micro-LEDs 610(2000) and620(2000), and each one of the micro-LEDs 610(2000) and 620(2000)includes the micro-LED structure 2000 described in the second embodimentillustrated in FIG. 2A. The other components of the micro-LED chip 14000of the embodiment illustrated in FIG. 14A are the same as the componentsof the micro-LED chip 13000 of the embodiment illustrated in FIG. 13A,and therefore detailed descriptions of these components are notrepeated.

Variation of Fourteenth Embodiment

FIG. 14B is a cross-sectional view of a micro-LED chip 14001, accordingto a variation of the fourteenth embodiment of the present disclosure.The micro-LED chip 14001 illustrated in FIG. 14B differs from themicro-LED chip 14000 illustrated in FIG. 14A in that the micro-LED chip14001 includes multiple metal layers 113 formed on the top surface 107 bof the top spacer 107 and between adjacent micro-LEDs 610(2000) and620(2000). The other components of the micro-LED chip 14001 of theembodiment illustrated in FIG. 14B are the same as the components of themicro-LED chip 13000 of the embodiment illustrated in FIG. 13A, andtherefore detailed descriptions of these components are not repeated.

In the embodiments illustrated in FIGS. 14A and 14B, each of themicro-LEDs 610 and 620 includes the micro-LED structure 2000 describedin the second embodiment illustrated in FIG. 2A. Alternatively, in otherembodiments, each of the micro-LEDs 610 and 620 may include any one ofthe micro-LED structures 2001, 2002, and 2003 described in the first,second, and third variations of the second embodiment illustrated inFIGS. 2B, 2C, and 2D, respectively.

Fifteenth Embodiment

FIG. 15A is a cross-sectional view of a micro-LED chip 15000, accordingto a fifteenth embodiment of the present disclosure. The embodimentillustrated in FIG. 15A differs from the embodiment illustrated in FIG.13A in that micro-LED chip 15000 includes two micro-LEDs 610(3000) and620(3000), and each one of the micro-LEDs 610(3000) and 620(3000)includes the micro-LED structure 3000 described in the second embodimentillustrated in FIG. 3A. The other components of the micro-LED chip 15000of the embodiment illustrated in FIG. 15A are the same as the componentsof the micro-LED chip 13000 of the embodiment illustrated in FIG. 13A,and therefore detailed descriptions of these components are notrepeated.

Variation of Fifteenth Embodiment

FIG. 15B is a cross-sectional view of a micro-LED chip 15001, accordingto a variation of the fifteenth embodiment of the present disclosure.The micro-LED chip 15001 illustrated in FIG. 15B differs from themicro-LED chip 15000 illustrated in FIG. 15A in that the micro-LED chip15001 includes multiple metal layers 113 formed on the top surface 107 bof the top spacer 107 and between adjacent micro-LEDs 610(3000) and620(3000). The components of the micro-LED chip 15001 of the embodimentillustrated in FIG. 15B are the same as the components of the micro-LEDchip 13000 of the embodiment illustrated in FIG. 13A, and thereforedetailed descriptions of these components are not repeated.

In the embodiments illustrated in FIGS. 15A and 15B, each of themicro-LEDs 610 and 620 includes the micro-LED structure 3000 describedin the third embodiment illustrated in FIG. 3A. Alternatively, in otherembodiments, each of the micro-LEDs 610 and 620 may include any one ofthe micro-LED structures 3001, 3002, and 3003 described in the first,second, and third variations of the third embodiment illustrated inFIGS. 3B, 3C, and 3D, respectively.

Sixteenth Embodiment

FIG. 16A is a cross-sectional view of a micro-LED chip 16000, accordingto a sixteenth embodiment of the present disclosure. The micro-LED chip16000 may include multiple micro-LEDs. At least one of the micro-LEDsincluded in the micro-LED chip 16000 may have any one of the micro-LEDstructures 4000, 4001, . . . 5003 described above.

In the embodiment illustrated in FIG. 16A, the micro-LED chip 16000includes two micro-LEDs 610(4000) and 620(4000). Each one of themicro-LEDs 610(4000) and 620(4000) includes the micro-LED structure 4000described in the fourth embodiment illustrated in FIG. 4A.

As illustrated in FIG. 16A, each one of the micro-LEDs 610(4000) and620(4000) includes the first type conductive layer 101, the second typeconductive layer 102 stacked on the first type conductive layer 101, andthe light emitting layer 103 formed between the first type conductivelayer 101 and the second type conductive layer 102. The profile of thefirst type conductive layer 101 perpendicularly projected on the bottomsurface 102 b of the second type conductive layer 102 is surrounded bythe bottom edge 102 a of the second type conductive layer 102. The lightemitting layer 103 extends along a horizontal level away from the topedge 101 a of the first type conductive layer 101 and the edge 103 a ofthe light emitting layer 103 is aligned with the bottom edge 102 a ofthe second type conductive layer 102.

Each one of the micro-LEDs 610(4000) and 620(4000) further includes thetop spacer 107 formed on the light emitting layer 103 and the bottomspacer formed under the light emitting layer 103. Both of the edge 107 aof the top spacer 107 and the edge 108 a of the bottom spacer 108 arealigned with the edge 103 a of the light emitting layer 103, which isaligned with the bottom edge 102 a of the second type conductive layer102.

The micro-LED chip 16000 further includes the top isolation layer 114surrounding the light emitting layer 103, and the microlens 111 formedon the second type conductive layer 102 and on a top surface 114 a ofthe isolation layer 114.

Except that the edge 103 a of the light emitting layer 103, the edge 107a of the top spacer 107, and the edge 108 a of the bottom spacer 108 arealigned with the bottom edge 102 a of the second type conductive layer102, the components of the micro-LED chip 16000 illustrated in FIG. 16Aare the same as the components of micro-LED chip 6005 illustrated inFIG. 6F, and therefore detailed descriptions of these components are notrepeated.

Variation of Sixteenth Embodiment

FIG. 16B is a cross-sectional view of a micro-LED chip 16001, accordingto a variation of the sixteenth embodiment of the present disclosure.The embodiment illustrated in FIG. 16B differs from the embodimentillustrated in FIG. 16A in that the micro-LED chip 16001 furtherincludes the metal layer 113 formed on the top surface 114 a of theisolation layer 114 and between adjacent micro-LEDs 610(4000) and620(4000). In the embodiment illustrated in FIG. 16B, there is only onemetal layer 113 between micro-LEDs 610(4000) and 620(4000).Alternatively, in other embodiments, there are multiple metal layers 113between micro-LEDs 610(4000) and 620(4000), and the number of themultiple metal layers 113 between micro-LEDs 610(4000) and 620(4000) maybe more than two. Except for the metal layer 113, the components of themicro-LED chip 16001 illustrated in FIG. 16B are the same as thecomponents of the micro-LED chip 16000 illustrated in FIG. 16A, andtherefore detailed descriptions of these components are not repeated.

In the embodiments illustrated in FIGS. 16A and 16B, each of themicro-LEDs 610 and 620 includes the micro-LED structure 4000 describedin the fourth embodiment illustrated in FIG. 4A. Alternatively, in otherembodiments, each of the micro-LEDs 610 and 620 may include any one ofthe micro-LED structures 4001, 4002, and 4003 described in the first,second, and third variations of the fourth embodiment illustrated inFIGS. 4B, 4C, and 4D, respectively.

Seventeenth Embodiment

FIG. 17A is a cross-sectional view of a micro-LED chip 17000, accordingto a seventeenth embodiment of the present disclosure. The micro-LEDchip 17000 includes two micro-LEDs 610(5000) and 620(5000). Each one ofthe micro-LEDs 610(5000) and 620(5000) includes the micro-LED structure5000 described in the fifth embodiment illustrated in FIG. 5A.

The micro-LED chip 17000 differs from the micro-LED chip 16000 in that aprofile of the second type conductive layer 102 perpendicularlyprojected on the top surface 101 d of the first type conductive layer101 is surrounded by the top edge 101 a of the first type conductivelayer 101. In addition, the edge 103 a of the light emitting layer 103,the edge 107 a of the top spacer 107, and the edge 108 a of the bottomspacer 108 are aligned with the top edge 101 a of the first typeconductive layer 101.

In addition, the micro-LED chip 17000 further includes the top isolationlayer 114 surrounding the light emitting layer 103. The microlens 111 isformed on the second type conductive layer 102 and on the top surface114 a of the isolation layer 114. The other components of the micro-LEDchip 17000 of the fourth embodiment illustrated in FIG. 17A are the sameas the components of the micro-LED chip 16000 of the second embodimentillustrated in FIG. 16A, and therefore detailed descriptions of thesecomponents are not repeated.

Variation of Seventeenth Embodiment

FIG. 17B is a cross-sectional view of a micro-LED chip 17001, accordingto a variation of the seventeenth embodiment of the present disclosure.The embodiment illustrated in FIG. 17B differs from the embodimentillustrated in FIG. 17A in that that the micro-LED chip 17001 furtherincludes the metal layer 113 formed on the top surface 114 a of theisolation layer 114 and between adjacent micro-LEDs 610(5000) and620(5000). In the embodiment illustrated in FIG. 17B, there is only onemetal layer 113 between micro-LEDs 610(5000) and 620(5000).Alternatively, in other embodiments, there are multiple metal layers 113between micro-LEDs 610(5000) and 620(5000), and the number of themultiple metal layers 113 between micro-LEDs 610(4000) and 620(4000) maybe more than two. Except for the metal layer 113, the components of themicro-LED chip 17001 illustrated in FIG. 17B are the same as thecomponents of the micro-LED chip 17000 illustrated in FIG. 17A, andtherefore detailed descriptions of these components are not repeated.

In the embodiments illustrated in FIGS. 17A and 17B, each of themicro-LEDs 610 and 620 includes the micro-LED structure 5000 describedin the fifth embodiment illustrated in FIG. 5A. Alternatively, in otherembodiments, each of the micro-LEDs 610 and 620 may include any one ofthe micro-LED structures 5001, 5002, and 5003 described in the first,second, and third variations of the fifth embodiment illustrated inFIGS. 5B, 5C, and 5D, respectively.

Comparative Example

FIG. 18 is a cross-sectional view of a micro-LED structure 1, accordingto a comparative example. The micro-LED structure 1 in the comparativeexample illustrated in FIG. 18 differs from the micro-LED structure 1000of the first embodiment illustrated in FIG. 1A in that the lightemitting layer 103 does not extend along the horizontal level away fromthe top edge 101 a of the first type conductive layer 101 and the bottomedge 102 a of the second type conductive layer 102. Instead, in thecomparative example, the edge 103 a of the light emitting layer 103 isaligned with both of the top edge 101 a of the first type conductivelayer 101 and the bottom edge 102 a of the second type conductive layer102.

As explained previously, the light emitting layer 103 may includemultiple pairs of quantum well layers. The number of multi-quantum well(MQW) pairs in the light emitting layer 103 is related to exposedsidewall area of the light emitting layer 103 which is generated by, forexample, inductively coupled plasma etching. The larger the exposedsidewall area, the more MQW pairs, resulting in larger surfacerecombination carrier loss.

In the comparative example, the sidewall of the light emitting layer 103is aligned with the edges 101 a and 102 a of the first type conductivelayer 101 and the second type conductive layer 102. As a result, largesurface recombination carrier loss may occur in the micro-LED betweenthe first type conductive layer 101 and the second type conductive layer102, negatively impacting the light emission efficiency of themicro-LED.

In contrast, in the first embodiment as well as other embodiments of thepresent disclosure, the light emitting layer 103 extends away from thetop edge 101 a of the first type conductive layer 101 and the bottomedge 102 a of the second type conductive layer 102, such that the edge103 a of the light emitting layer 103 does not contact the top edge 101a of the first type conductive layer 101 and the bottom edge 102 a ofthe second type conductive layer 102. As a result, surface recombinationcarrier loss may not occur in the micro-LED between the first typeconductive layer 101 and the second type conductive layer 102.Consequently, light emission efficiency of the micro-LED will beimproved.

While illustrative embodiments have been described herein, the scope ofthe present disclosure covers any and all embodiments having equivalentelements, modifications, omissions, combinations (e.g., of aspectsacross various embodiments), adaptations and/or alterations as would beappreciated by those skilled in the art based on the present disclosure.For example, features included in different embodiments shown indifferent figures may be combined. The limitations in the claims are tobe interpreted broadly based on the language employed in the claims andnot limited to examples described in the present specification or duringthe prosecution of the application. The examples are to be construed asnon-exclusive. It is intended, therefore, that the specification andexamples be considered as illustrative only, with a true scope andspirit being indicated by the following claims and their full scope ofequivalents.

What is claimed is:
 1. A micro-LED chip including multiple micro-LEDs,wherein, at least one micro-LED of the multiple micro-LEDs comprises: afirst type conductive layer; a second type conductive layer stacked onthe first type conductive layer; and a light emitting layer formedbetween the first type conductive layer and the second type conductivelayer, wherein the light emitting layer extends along a horizontal levelfrom a top edge of the first type conductive layer and a bottom edge ofthe second type conductive layer, such that an edge of the lightemitting layer does not contact the top edge of the first typeconductive layer and the bottom edge of the second type conductivelayer, and a profile of the second type conductive layer perpendicularlyprojected on a top surface of the first type conductive layer issurrounded by an edge of the first type conductive layer, and themicro-LED chip further includes a metal layer formed on a portion of thelight emitting layer that extends from the top edge of the first typeconductive layer.
 2. The micro-LED chip according to claim 1, whereinthe metal layer is formed on a surface of the light emitting layer anddoes not contact the first type conductive layer or the second typeconductive layer.
 3. The micro-LED chip according to claim 1, wherein alateral dimensional value of the metal layer is not more than a distancebetween an edge of the light emitting layer and the top edge of thefirst type conductive layer.
 4. The micro-LED chip according to claim 3,wherein the lateral dimensional value of the metal layer is from 2 nm to10 um.
 5. The micro-LED chip according to claim 1, wherein a centerpoint of the metal layer is aligned with a center point between adjacentmicro-LEDs.
 6. The micro-LED chip according to claim 1, wherein a centerpoint of the metal layer is near one of adjacent micro-LEDs.
 7. Themicro-LED chip according to claim 1, wherein the metal layer comprises aplurality of metal layers, and the plurality of metal layers arearranged in parallel along a surface of the light emitting layer.
 8. Themicro-LED chip according to claim 1, wherein a material of the metallayer includes a high work function metal material which matches amaterial of the light emitting layer.
 9. The micro-LED chip according toclaim 8, wherein the high work function metal material includes at leastone of gold, platinum, palladium, beryllium, cobalt, nickel, ortungsten.
 10. The micro-LED chip according to claim 1, wherein the lightemitting layer is continuously formed on the micro-LED chip.
 11. Themicro-LED chip according to claim 1, wherein the multiple micro-LEDsshare the light emitting layer.
 12. The micro-LED chip according toclaim 1, further comprising: a top spacer formed on a top surface of thelight emitting layer; a bottom spacer formed on a bottom surface of thelight emitting layer, wherein an edge of the top spacer is aligned withan edge of the light emitting layer, and an edge of the bottom spacer isaligned with the edge of the light emitting layer.
 13. The micro-LEDchip according to claim 12, wherein a thickness of the top spacer islarger than a thickness of the light emitting layer, and a thickness ofthe bottom spacer is larger than the thickness of the light emittinglayer.
 14. The micro-LED chip according to claim 12, further comprising,in the at least one micro-LED, a microlens formed on the second typeconductive layer and on a top surface of the top spacer.
 15. Themicro-LED chip according to claim 1, wherein a top area of the firsttype conductive layer is larger than a bottom area of the first typeconductive layer, and a top area of the second type conductive layer issmaller than a bottom area of the second type conductive layer.
 16. Themicro-LED chip according to claim 1, wherein the light emitting layerincludes only one pair of quantum well layers, or multiple pairs ofquantum well layers.
 17. The micro-LED chip according to claim 1,wherein the at least one micro-LED further comprises a reflectivestructure formed surrounding the first type conductive layer.
 18. Themicro-LED chip according to claim 17, wherein, in the at least onemicro-LED, the reflective structure is attached on a sidewall surface ofthe first type conductive layer, and the at least one micro-LED furthercomprises a bottom connection structure formed under the first typeconductive layer and electrically connected with the first typeconductive layer.
 19. The micro-LED chip according to claim 18, furthercomprising a substrate under the first type conductive layer, andelectrically connected with the bottom connection structure by aconnecting pad in the substrate.
 20. The micro-LED chip according toclaim 18, wherein the bottom connection structure is made of areflective and electrically conductive material.